Synchronously programmed sample dilutor apparatus

ABSTRACT

A single rotary cam in a liquid sample dilutor has multiple mechanical actuator program cycle profiles, which during one cam cycle sequentially actuate the cam arc intervals which determine the liquid volume inputs into and the outputs from a mixing cup in which a selected sample liquid volume, a selected diluent liquid volume, the sample and diluent liquid mixture volume, the diluted liquid sample volume aspiration time interval, the waste diluted sample liquid volume removal, and the diluent liquid volume waste rinse and ejection are controlled. The cam member mechanically actuates the pistons of the three liquid volume measuring syringes, the system slider valve, the aspirator probe, and the sample probe, operatively cooperating in sample and diluent volume measurement, and diluted sample volume withdrawal from the dilutor.

States Unite Klein 41 SYNCHRONOUSLY PRoG i SAMPLE DILUTOR APPTU [52] US. Cl. ..73/423 A, 23/259 [51] Int. Cl. ..GOln 1/14 [58] Field of Search ..73/423 A, 425.6;

[ 5 6 References Cited UNITED STATES PATENTS 7/1959 Von Rabenau ..74/567 6/1965 Baruch et al. ..73/423 Primary ExaminerS. Clement Swisher v AttorneyThomas L. Peterson et al.

[ ABSTRACT A single rotary cam in a liquid sample dilutor has multiple mechanical actuator program cycle profiles, which during one cam cycle sequentially actuate the cam arc intervals which determine the liquid volume inputs into and the outputs from a mixing cup in which a selected sample liquid volume, a selected diluent liquid volume, the sample and diluent liquid mixture volume, the diluted liquid sample volume aspiration time interval, the waste diluted sample liquid volume removal, and the diluent liquid volume waste rinse and ejection are controlled. The cam member mechanically actuates the pistons of the three liquid volume measuring syringes, the system slider valve, the aspirator probe, and the sample probe, operatively cooperating in sample and diluent volume measurement, and diluted sample volume withdrawal from the dilutor.

15 Claims, 5 Drawing Figures SYNCI'IRONOUSLY PROGRAMMED SAMPLE DILUTOR APPARATUS BACKGROUND OF THE INVENTION This invention relates to an automated liquid sample dilutor, suitable for supplying diluted liquid sample to the sample intake of an analyzer apparatus.

A sample supply apparatus relating to the present invention is disclosed in U.S. Pat. No. 3,240,070 to Martin & Johnson. A simple feeding device is provided capable of feeding a plurality of different liquid samples to an analyzing apparatus or the like without any sample delivery tube connected between them. In U.S. Pat. No. 3,127,062, Feichtmeir and Jenkins provide an apparatus for the measurement and dilution of fluid samples semi-automatically expediting the taking and admixing of predetermined volumes of a sample fluid and a diluent or reagent fluid. Rosen, in U.S. Pat. No. 3,197,285 discloses an apparatus for rapidly withdrawing from specimen tubes, for purposes of analysis, a succession of precisely measured small volumes of blood serum for delivery, along with an equally precisely measured quantity of a reagent, to be delivered to a series of containers.

In Winter, U.S. Pat. No. 3,08 l ,158 a liquid treatment apparatus is disclosed providing a plurality of sets of liquid containers operable automatically in conjunction with a plurality of companion liquid take-off devices, for supplying a plurality of liquids from companion containers of the different sets respectively to a liquid processing apparatus. In U.S. Pat. No. 3,038,340, Isreeli provides an apparatus for automatically feeding in succession a plurality of different liquid samples to an analyzer apparatus. Skeggs, in U.S. Pat. No. 2,879,141 provides an apparatus for automatically feeding in succession a plurality of different liquid samples to an analyzer apparatus.

SUMMARY OF THE INVENTION An automated liquid sample dilutor supplies a diluted liquid sample to the sample intake of a chemical analyzer apparatus. A single rotary program cam is driven by a low rpm power means such as an electrical motor. The cam repetitively actuates a 360 rotary timing cycle. The program cam has disposed therein multiple fixed mechanical actuator program profile means which sequentially actuate and control fixed cycle are interval portions. The single program cam controls the liquid sample intake probe position, the sample liquid volume, the diluent liquid volume, the sample and diluent liquid mixture volume, the aspirator probe position, the diluted liquid volume aspirating time interval, the waste diluted sample liquid volume removal, and the diluent liquid volume waste rinse input to and output from a mixing cup. Cooperatively associated with the program cam are cam followers, positionable sample intake probe components, sample liquid measuring components, diluent liquid measuring components, sample and diluent liquid mixing components, diluted sample liquid aspirating components, sample diluent liquid rinsing and ejecting components, and sample liquid pumping and valving components.

Other aspects and advantages of this invention are taught in the following description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS The description of this invention is to be read in conjunction with the following drawings:

FIG. I is a perspective partially exploded drawing of the dilutor apparatus, illustrating the single rotary programming cam and power means operating the cam, in a rotary timing cycle providing the synchronous sequential predetermined arc interval portions of the timing cycle.

FIG. 2 is a schematic illustration of the fluid flow circuits of the dilutor apparatus.

FIG. 3A is a plan view of one face of a program cam of this invention.

FIG. 3B is the opposed face of the program cam of FIG. 3A.

FIG. 4 is a schematic diagram of the timing cycle embodied in the program cam illustrated in FIGS. 3A and 38.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 in detail, the dilutor 1 is shown in an exploded view with essential operative components disposed in a cooperative array. The program cam 2 is secured to the shaft 3a of power means 3. Typically, power means 3 is a high torque low speed motor, 4 RPM or the like, whose shaft 30 extends through the metal mounting plate 33. The movable sample liquid volume intake tube probe 4 has a hydrophobic plastic tip 32, moved by the follower 5 which engages an unseen program profile means for probe 4, in the unseen face of cam 2. The movable sample aspirator probe 6 has a cam follower 7 which also engages a second unseen program profile means actuating probe 6, in the unseen face of cam 2. The piston groove program cycle 10 and the valve program cycle 11 are shown disposed in the face of cam 2. All program cycles are discussed in detail later.

The pair of switch actuating means 12 and 13 are shown as lobes oppositely disposed on the cam diameter on the cam face parallel to the cam axis of rotation. The switch lobe means 12 and 13 actuate the microswitch component 31 as the cam 2 rotates.

The slider valve 16 is shown slidably mounted in the pump block mounting plate 17, the cam follower 15 of the valve 16 being operatively disposed in the valve groove program cycle II. The slider valve aperture 30 transfers fluid flow through mating ports, not shown, on a pump block 18, as the valve 16 is oscillated vertically by the cam 2. The valve aperture 29 is connected to the diluent pump piston 21 in the manner shown schematically in FIG. 2.

The pump block 18 is operatively mounted on the face of the pump block mounting plate 17. The pump block 18 contains the three integral syringes; sample liquid syringe 20 with its piston 23, diluent liquid syringe 21 with its piston 24, and drain liquid syringe 22 with its piston 25. The three pistons 23, 24, 25 are collectively operatively secured in the piston carriage 14. The carriage 14 is operatively secured to the piston follower 27 which is slidably disposed on the piston carriage mounting shaft 19. The piston follower 27 is operatively disposed in the piston groove program cycle 10. Thus all three pistons 23, 24, 25 are concurrently slidably engaged in motion during the dilutor 1 operation. A cam 26 is disposed for manual adjustment of the sample piston 23 linear travel distance, regulating the ratio of sample liquid to diluent liquid mixed in the dilutor 1 operation.

The stirring arm 28 is vibrated electromagnetically, on signal, stirring the diluted sample liquid disposed in the mixing cup 52. A waste drain tube probe 34 is secured in the mixing cup 52. The probe 34 provides means of draining waste diluted sample liquid and rinse diluent liquid from cup 52.

Referring to FIG. 2 in detail, the schematic diagram illustrates the fluid flow of the sample liquid and the diluent liquid through the dilutor apparatus 1 of FIG. 1. The schematic dilutor 50, equivalent to dilutor apparatus 1, illustrates a sample intake probe 51 disposed in a position suitable for sample volume intake, together with an alternate sample intake tube probe 51 position disposed in a mixing cup 52 where a liquid sample can be ejected into cup 52. An aspirator tube probe 53 is also shown disposed in the cup 52, positioned for aspiration of liquid from the cup 52. In an alternate position, the aspirator probe 53 is disposed above and external to the liquid contained in the cup 52. A drain tube probe 54 is shown permanently disposed in a position suitable for withdrawing all liquid sample from the cup 52. A drain check valve 55 is connected in a T-Tube portion of the flow circuit to the drain tube probe 54, a drain waste tube line 56, and a drain syringe 57. The syringe 57 is filled with liquid waste from the mixing cup 52, by withdrawing the drain piston 58 in a predetermined process, from the drain syringe 57. A sample syringe 59 has a sample piston 60 disposed therein, the syringe 59 being connected to the sample intake probe 51. A schematic tube connection 61 can conduct the liquid between the syringe 59 and a slide valve 62. The slide valve 62 can connect diluent syringe 64 through the schematic connection tube 63 to the sample syringe 59. The diluent syringe piston 65 evacuates diluent liquid into syringe 64 through the schematic intake tube connection 66 from a diluent liquid supply disposed exteriorly to the dilutor apparatus 50, when the slide valve 62 connects 66 and 64 through 63, enabling diluent liquid to be taken in without disturbing the flow of sample liquid into sample syringe 59. The arrow 67 represents the diluent liquid intake flow direction in the schematic analyzer 50. 68 represents the diluted sample liquid direction of flow through asperator probe 53 to an external analyzer. Arrow 69 represents the flow direction of sample liquid volume into the syringe 59, and 69' represents the op posite flow direction of the sample liquid volume into the mixing cup 52. Arrow 70 represents the direction of diluent liquid volume flow from the mixing cup 52 into the waste syringe 57, then eventually the volume flows into the waste disposal tube line 56.

FIGS. 3A and 38 together illustrate the pair of opposed faces of the program cam 2 which are disposed normal to the axis of rotation of cam 2. The program cam 2 is an example of a preferred program cam operative in the typical dilutor 1, 50, or the like. FIGS. 3A and 3B illustrate the construction of the program cam 2, and its operation in a typical timing cycle is further illustrated in FIG. 4. In FIG. 3A the cam face 2' as illustrated has a piston groove program cycle and a valving program cycle 11 disposed therein. A power shaft 3a is shown concentrically disposed at the cam center and is secured to cam hub 100. Cam switch fixed actuator means 12 and 13 are diametrically oppositely disposed on the cam face which is parallel to the cam axis of rotation. The cam 2 rotates in the direction of arrow 105. One of the pair of switch actuating means lobe 13 is positioned to terminate the first one-half of the timing cycle and the second of the pair of switch actuating means 12 is positioned to stop the cam at the end of the full 360 rotary timing cycle. The piston groove program cycle 10 and the valve groove program cycle 1 l are specific examples taught herein of the multiple fixed mechanical actuator program profile means disposed in a program cam. The program profile means 10 and 11 are synchronously sequentially disposed in fixed predetermined cycle are interval portions, operatively associated with cam followers and other components of the dilutor 1, 50, or the like. Specifically herein, each program profile means will be described in terms of an arc interval of the 360 cycle disposed in the cam, each portion of the arc interval adapted to providing a specific operative step in the dilutor program.

The piston groove program cycle 10 is initially traversed from the cam diarnetrical start line 106, the cam follower 27, or the like, of FIG. 1, being positioned at the end of arc interval (P1). The three grouped syringes 20, 21, 22, together with their respective grouped pistons 23, 24, 25 of FIG. 1 are equivalent to the respective three schematicized syringes 59, 64, 57 and their respective pistons 60, 65 and 58 of the schematic FIG. 2. After a very short cycle rest interval, which will be described later, the three grouped pistons 23, 24, 25 of FIG. 1, or the equivalent pistons 60, 65, 58 of FIG. 2, are drawn down during the arc interval 1 1 l, intaking liquids.

The explanation of the letters, such as 110 (P1) in parenthesis will be made later in conjunction with FIG. 4. During the traverse of arc interval 112 the above pistons remain unchanged at their maximum extension in the syringes. During the arc interval 113 traverse the pistons 60, 65, 58 deliver the liquids contained in the respective syringes 59, 64, 57. During the traverse of arc interval 114 there is no change in the piston positions, which are now fully engaged in the respective syringe chambers. In the traverse of arc interval 107 the pistons are again being withdrawn from the syringes. During the traverse of arc interval 108 the piston positions remain unchanged at their maximum extension from the respective syringes. During the traverse of arc interval 109 the pistons are again delivering liquids from the respective syringes. During the traverse of arc interval 110 the pistons remain fully engaged in the syringes, slightly past the start of a new 360 timing program cycle.

Concurrently with the operation of the piston group program cycle 10, the valve groove programming cycle 11, operates the slider valve 16 shown in FIG. 1, and the equivalent schematically illustrated valve 62 in FIG. 2. The slider valve 62 is thus also mechanically operated in a synchronous sequential program over predetermined cycle are interval portions. With the start of the cycle at 106, the traverse of arc interval 115, the slider valve 62 is disposed in an intake aperture position allowing flow of sample liquid volume into syringe 59 and diluent liquid volume into syringe 64 of the schematic of FIG. 2, without the volumes mixing. During the traverse of arc interval 116 the slider valve 62 is repositioning. The valve 62 is open to the sample liquid tube probe 51 during the traverse of arc interval 117. During arc interval 118 traverse the valve 62 is repositioning, and is closed to all fluid flow. The traverse of arc interval 119 opens the valve 62 to flow into the syringes. The valve 62 is changing aperture position during arc interval 120, and remains closed during the traverse of arc interval 121, finally opening during the traverse of arc interval 122 to complete the 360 timing cycle.

FIG. 38 illustrates the obverse side of the program cam 2 showing the cam face 2" having the sample probe groove program cycle 150 and the aspirator probe groove program cycle 151 disposed therein. The configuration shown in FIG. 3B is obtained by rotating the cam 2 through 180 as compared to FIG. 3A. Again, as in FIG. 3A, the predetermined cycle interval portions are illustrated by the arc intervals denoted by brackets for each arc interval. The cam direction of rotation 105, is initiated at the cam start position 152, being equivalent to the cam start position 1 of FIG. 3A

The traverse of the arc interval 153 controls the sample intake probe position during sample intake into the syringe 59. The traverse of arc interval 154 controls the sample probe elevation above the sample cup 52. The are interval 155 controls the translation of the sample probe 51 to a position above the mixing cup 52, finally becoming the positioned probe 51' of FIG..2. The traverse of arc interval. 156 positions the sample probe during delivery of the sample liquid volume and the diluent liquid volume into the mixing cup 52. A onehalf timing cycle interval is represented by the cam diameter point 157 being rotated to the original position of the cam point 152 and stopping, allowing the chemical analyzer connected to the dilutor to aspirate a diluted and mixed liquid sample for further chemical analysis. During the traverse of arc interval 158 an air sample is drawn into the sample probe as the sample probe is translated toward the position 51', and the diluted liquid volume in the mixing cup 52 is drawn into the drain syringe 57. During the traverse of arc interval 159, diluent rinse solution is delivered through the sample probe 51' into the mixing cup 52 and the sample probe 51' is dipped into the diluent rinse solution to further clean the hydrophobic probe tip 32. During the traverse of arc interval 160 the sample probe 51 tip is withdrawn from the rinse solution in the mixing cup 52. Over the arc interval 161 the previously rinsed sample probe 51' tip is translated to the sample intake 51 position, prior to initiating another sample intake. In the traverse of the final arc interval 162, the sample probe 51 is disposed in the sample intake position at rest.

Concurrently with the operation of the sample intake probe 51, the aspirator probe groove program cycle 151 is cooperative with the aspirator probe 53. In order to clarify the aspirator probe operation, consider the aspirator probe traverse of arc interval 170, shown in FIG. 31.3 prior to the stop 157 at one-half of the timing cycle. The are interval is cooperatively traversed, dropping the aspirator probe 53' into the mixing cup 52, the probe 53 then being positioned for aspiration of a diluted liquid sample into a chemical analyzer or the like for analysis. After a suitable volume of diluted sample is aspirated, either on manual or automatic signal, the last of the timing cycle is again initiated at 157. The arc interval 171 cooperatively functions to retract the aspirator probe 53 above the mixing cup 52, where the aspirator probe 53 remains during the arc angle represented by 172-173 over the remainder of the cam cycle.

FIG. 4 is a schematic representation of a full 360 timing cycle of the program cam. In order to clarify the significance of FIG. 4 in relation to the program profile means specifically illustrated in FIGS. 3A and 3B, notations have been made on FIG. 4 which are correlated on arc intervals of the program profile means 10, 11, 150, and 151 of FIGS. 3A and 3B. In FIG. 1 the three syringes 21, 22 and 23 are shown mounted and secured to a single piston carriage follower 14 so that the pistons 23, 24, 25 move in unison in filling and emptying the three syringes. Thus P1, P2, P3 and P4 consecutively indicate: P1 denotes syringes completely filled with pistons, P2 indicates the three syringes being filled by distending the pistons in the syringes, P3 indicates the three syringes completely filled with liquid, and P4 indicates the three syringes being concurrently emptied of liquids. Further in FIG. 4, the slider valve, typically 16 of FIG. 1, or 52 of FIG. 2, is operatively shown; V1 as being open for the filling of the syringes, V2 as transferring, and V3 as closed to liquid intake during the emptying of the syringes, and V4 as transferring again.

The schematic representation of the position of the sample liquid probe 51 is shown with S1 representing the sample probe 51 disposed outside of the sample cup 52 in a sample collecting position, S2 representing the sample probe being elevated into position adjacent to the cup 52, S3 representing the sample probe 51 being moved above the cup, and S4 representing the sample and diluent liquid being ejected through the sample probe into the cup. The aspiration interval is at the end of the first one-half timing cycle. S5 represents the sample probe 51 positioned above the mixing cup 52 during the intake of a volume of air. A diluent rinse volume is ejected into a mixing cup 52, or the like, and the sample probe 51' is dipped in the rinse volume in the cup during arc interval Sh. During arc interval $7 the sample probe 51' is retracted from the cup 52. During arc interval S8 the probe 51 is translated horizontally, and finally brought to rest in sample probe intake position as probe 51 during arc interval S9.

Concurrently the aspirator probe 53' is shown disposed above the cup from the beginning of the cycle through the interval A1 until nearly the end of the first one-half timing cycle. At that time the aspirator probe 53 is dipped (A2) into the cup 52 and remains at rest in the mixing cup 52 (A3). During the time (A3) the aspirator probe 53 remains in the mixing cup 52, the mixed diluent sample is aspirated into the chemical analyzer secured to the aspirator probe 53. When the second one-half of the timing cycle is initiated, the aspirator probe is lifted from the mixing cup during the interval A4 and remains disposed above the mixing cup during the remainder of the second one-half cycle, during the further interval A1. A partial switch cycle SW 1 is shown in the figure at the beginning of the first onehalf of the cycle, the cycle being initiated manually or by automatic signal, from an external source such as the chemical analyzer, a sample turntable, a data printer, or the like. After the first one-half of the timing cycle is completed by SW2, the second one-half of the timing cycle can be initiated manually or by one of the switching instrument means described above.

The operational cycle of the dilutor can be described in conjunction with the schematic of FIG. 2. At the beginning of the operation cycle, the sample probe 51 is disposed in a position outside of the mixing cup 52, ready to receive a fresh sample liquid for analysis. The slider valve 62 is in a position to receive diluent liquid volume only. The three pistons 58, 60 and 65 are then concurrently drawn down, intaking a sample liquid volume through the sample probe 52, and a diluent liquid volume through the slider valve 62. Any liquid sample or residue of wash remaining in the cup 52 is extracted by the drain piston 58 drawing the residue into the syringe 57. The sample probe 51 is then slowly withdrawn under the control of the sample probe groove program cycle 150, from the sample solution upward into the instrument and positioned above the mixing cup 52. The sample liquid volume is then injected into the mixing cup 52 with the diluent liquid volume from the syringe 64 flowing immediately behind it through the repositioned slider valve 62, the slider valve 62 now being in the position corresponding to the functioning arc interval 117. The vibrating electromagnetic stirrer (as shown as 28 in FIG. 1), then cooperatively operates to agitate the mixed sample volume and the diluent volume, producing uniform mixing in the mixing cup 52. The aspirator probe 53 is then disposed in the mixing cup 52 and the first onehalf of the timing cycle is complete. The dilutor unit comes to a stop, allowing an appropriate time interval for the aspiration of the diluted sample volume into a chemical analyzer connected to the aspirator probe 53.

After aspiration of the mixed diluted sample is completed, the wash cycle, being the latter one-half of the 360 timing cycle, is initiated. The three pistons 58, 60, 65 are concurrently drawn down with the slider valve 62 in the position of drawing fresh liquid diluent through the line 66 into the diluent syringe 64, and a slug of air is drawn into the sample syringe 59 through the sample probe tip 51 now disposed up above the mixing cup 52. Concurrently, unused diluted sample liquid in the mixing cup 52 is drawn into the drain syringe 57. As the cycle continues, the slider valve 62 shifts to an opposed position and the three pistons 58, 60 and 65 reverse their travel. Fresh diluent is then injected into the mixing cup 52 and the diluent fluid sample volume which was in the drain syringe 57 is exhausted through the check valve 55 into the waste line 56. The fresh diluent liquid which has been injected into the mixing cup 52, now called a rinse solution, rinses the mixing cup and the sample probe 51' which has dropped into the cup and into the rinse solution. After the sample probe 51' is washed in the fresh diluent solution, it is slowly withdrawn from the solution and returned to a position outside of the mixing cup readyto receive the next sample volume for analysis.

The hydrophobic plastic tip 32 of tube probe 4 is typically a hollow tube formed of polyethylene, polypropylene, polytetra fluoroethylene, or the like,

not wet by aqueous solutions. If the linear withdrawal velocity of the tip from an aqueous solution in the mixing cup 52, or the like, is less than 1 inch per second, the tip does not extract or form a pendant liquid drop on retraction from the aqueous surface. The limited withdrawal rate thus results in a more accurate mixture ratio of liquid sample volume and diluent liquid volume.

Typically the cam cycle utilizing a 4 RPM motor means 3 is 15 seconds for a complete 360 cycle. For many applications it is desirable to prepare as many diluted samples as quickly as possible. A preferred half timing cycle, excluding sample aspiration time is 10 seconds.

An elongated cylinder cam device can likewise be used as a program cam, having multiple fixed mechanical actuator program profile means synchronously sequentially disposed on the one cylindrical surface of the cam, including the cam switch fixed actuated means. By suitably disposing spring loaded cam followers cooperatively adjacent to the profile means, one can cause the profile means to mechanically actuate the components of the dilutor in a manner equivalent to that previously described.

Groove program cycles have been specifically described herein. However, positive or raised land program cycle means are equivalent and may be disposed on the cam faces of the disc described in FIGS. 3A and 38, as well as on the drum cam described just above.

Obviously, many modifications and variations of this improvement in a synchronously programmed sample dilutor apparatus are possible in the light of the above teachings. It is therefore understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Iclaim:

1. In an automated liquid sample dilutor, suitable for supplying diluted sample to the sample intake for a chemical analyzer or the like, the combination comprising:

a single rotary program cam, and power means for rotating said cam, said cam repetitively programming a 360 rotary timing cycle, said program cam having disposed therein multiple fixed mechanical actuator program profile means synchronously sequentially controlling over predetermined cycle arc intervals the sample intake probe position, the sample liquid volume, the diluent liquid volume, the sample and diluent liquid mixture volume, the aspirator probe position, the diluted sample liquid volume aspiration time interval, the waste diluted sample liquid volume removal, and the diluent liquid volume waste rinse and ejection inputs to and outputs from a mixing cup.

2. A sample dilutor as set forth in claim 1 wherein said program cam has at least two discrete mechanical actuator program profile cycle means disposed on each one of the pair of cam faces normal to the cam axisof rotation.

13. A sample dilutor as set forth in claim 1 wherein said program cam has at least each one of a pair of cam switch fixed actuating means diametrically oppositely disposed on the cam face parallel to said cam axis of rotation, one of said pair of switch actuating means positioned to terminate the first one-half of said cycle, and the second of said pair of switch means positioned to terminate the second one-half of said cycle.

4. A sample dilutor as set forth in claim 1 wherein the timing one-half cycle of said program cam is less than 10 seconds.

5. An apparatus as set forth in claim 1 wherein a hydrophobic sample probe tip is removed from an aqueous sample liquid surface at a linear velocity of less than 1.0 inch per second.

6. In an automated liquid sample dilutor, suitable for supplying diluted samples to the sample intake of a chemical analyzer or the like, the combination comprising:

a single rotary program cam and power means for rotating said cam, said cam repetitively programming a 360 rotary timing cycle, said program cam having disposed therein multiple fixed mechanical actuator program profile means synchronously sequentially controlling over predetermined arc intervals of said cycle, the sample intake probe position, the sample liquid volume, the diluent liquid volume, the sample and diluent liquid mixture volume, the aspirator probe position, the diluted sample liquid volume aspiration time interval, the waste diluted sample liquid volume removal, and the diluent liquid volume waste rinse and ejection inputs to and outputs from a mixing cup; and

sample intake probe means, sample liquid measuring means, diluent liquid measuring means, sample and diluent liquid mixing means, diluted sample liquid ejecting means, system diluent liquid rinsing and ejecting means, system liquid pumping and valving means operatively associated with said program cam.

7. A sample dilutor as set forth in claim 6 wherein said program cam has at least two discrete mechanical actuator program profile means disposed on each one of the pair of cam faces normal to the cam axis of rotation.

8. A sample dilutor as set forth in claim 6 wherein said program cam has at least each one of a pair of cam switch fixed actuating means diametrically oppositely disposed on the cam face parallel to said cam axis of rotation, one of said pair of switch actuating means positioned to terminate the first one-half of said cycle and the second of said pair of switch actuating means positioned to terminate the second one-half of said cycle.

9. A sample dilutor as set forth in claim 6 wherein the timing one-half cycle of said program cam is less than l0 seconds.

10. An apparatus as set forth in claim 6 wherein a hydrophobic sample probe tip is removed from an aqueous sample liquid surface at a linear velocity of less tan 1. inch per second.

ll. ln an automated liquid sample dilutor, suitable for supplying diluted samples to the intake of a chemical analyzer or the like, the combination comprising:

a single rotary program cam, and power means for rotating said cam, said cam repetitively programming a 360 rotary timing cycle, said cam having a fixed piston groove first program cycle filiiflfi it i riiifihlif'c ofifiii the above first and second program cycles having a constant groove depth, said cam having a fixed aspirator, constant depth groove third program cycle and a fixed sample probe, variable depth groove fourth program cycle disposed on the second cam face of said cam opposite said first cam face, said first and second cam faces disposed normal to the cam axis of rotation, said cam having at least a pair of fixed switch actuating lobes symmetrically oppositely disposed on the cam face parallel to said cam axis of rotation, one of said pair of switch lobes positioned to terminate the first one-half of said timing cycle, the above said programming cycles and said switch lobes synchronously sequentially disposed to control predetermined arc intervals of said cycle relating to sample intake probe position, the sample liquid volume, the diluent liquid volume, the sample and diluent liquid mixture volume, the diluted sample liquid volume aspiration, and the system diluent liquid rinse volume and ejection.

12. A sample dilutor as set forth in claim 11 wherein the timing one-half cycle of said program cam is less than 10 seconds.

13. An apparatus set forth in claim 11 wherein a hydrophobic sample probe tip is removed from an aqueous sample liquid surface at a linear velocity of less than 1. inch per second.

14. In an automated liquid sample handling device suitable for supplying sample to the sample intake of a chemical analyzer, said device including pump means, valve means for controlling the flow of liquid to and from said pump means, a sample intake and delivery probe, an aspirator probe for connection to said analyzer and a sample cup, the improvement which comprises:

a single rotary program cam and power means for rotating said cam, said cam having formed therein multiple program profile means for sequentially controlling over a predetermined cycle the operation of said pump and valve means, and the position of said sample intake and delivery probe and said aspirator probe with respect to said sample cup, said profile means effecting vertical and horizontal translation of said sample intake and delivery probe and vertical translation of said aspirator probe.

15. A device as set forth in claim 14 wherein said program cam has at least two discrete profile means disposed on each one of the pair of cam faces normal to the cam axis of rotation. 

1. In an automated liquid sample dilutor, suitable for supplying diluted sample to the sample intake for a chemical analyzer or the like, the combination comprising: a single rotary program cam, and power means for rotating said cam, said cam repetitively programming a 360* rotary timing cycle, said program cam having disposed therein multiple fixed mechanical actuator program profile means synchronously sequentially controlling over predetermined cycle arc intervals the sample intake probe position, the sample liquid volume, the diluent liquid volume, the sample and diluent liquid mixture volume, the aspirator probe position, the diluted sample liquid volume aspiration time interval, the waste diluted sample liquid volume removal, and the diluent liquid volume waste rinse and ejection inputs to and outputs from a mixing cup.
 2. A sample dilutor as set forth in claim 1 wherein said program cam has at least two discrete mechanical actuator program profile cycle means disposed on each one of the pair of cam faces normal to the cam axis of rotation.
 3. A sample dilutor as set forth in claim 1 wherein said program cam has at least each one of a pair of cam switch fixed actuating means diametrically oppositely disposed on the cam face parallel to said cam axis of rotation, one of said pair of switch actuating means positioned to terminate the first one-half of said cycle, and the second of said pair of switch means positioned to terminate the second one-half of said cycle.
 4. A sample dilutor as set forth in claim 1 wherein the timing one-half cycle of said program cam is less than 10 seconds.
 5. An apparatus as set forth in claim 1 wherein a hydrophobic sample probe tip is removed from an aqueous sample liquid surface at a linear velocity of less than 1.0 inch per second.
 6. In an automated liquid sample dilutor, suitable for supplying diluted samples to the sample intake of a chemical analyzer or the like, the combination comprising: a single rotary program cam and power means for rotating said cam, said cam repetitively programming a 360* rotary timing cycle, said program cam having disposed therein multiple fixed mechanical actuator program profile means synchronously sequentially controlling over predetermined arc intervals of said cycle, the sample intake probe position, the sample liquid volume, the diluent liquid volume, the sample and diluent liquid mixture volume, the aspirator probe position, the diluted sample liquid volume aspiration time interval, the waste diluted sample liquid volume removal, and the diluent liquid volume waste rinse and ejection inputs to and outputs from a mixing cup; and sample intake probe means, sample liquid measuring means, diluent liquid measuring means, sample and diluent liquid mixing means, diluted sample liquid ejecting means, system diluent liquid rinsing and ejecting means, system liquid pumping and valving means operatively associated with said program cam.
 7. A sample dilutor as set forth in claim 6 wherein said program cam has at least two discrete mechanical actuator program profile means disposed on each one of the pair of cam faces normal to the cam axis of rotation.
 8. A sample dilutor as set forth in claim 6 wherein said program cam has at least each one of a pair of cam switch fixed actuating means diametrically oppositely disposed on the cam face parallel to said cam axis of rotation, one of said pair of switch actuating means positioned to terminate the first one-half of said cycle and the second of said pair of switch actuating means positioned to terminate the second one-half of said cycle.
 9. A sample dilutor as set forth in claim 6 wherein the timing one-half cycle of said program cam is less than 10 seconds.
 10. An apparatus as set forth in claim 6 wherein a hydrophobic sample probe tip is removed from an aqueous sample liquid surface at a linear velocity of less tan
 1. inch per second.
 11. In an automated liquid sample dilutor, suitable for supplying diluted samples to the intake of a chemical analyzer or the like, the combination comprising: a single rotary program cam, and power means for rotating said cam, said cam repetitively programming a 360 * rotary timing cycle, said cam having a fixed piston groove first program cycle and a fixed valve groove second program cycle disposed on a first face of said cam, each one of the above first and second program cycles having a constant groove depth, said cam having a fixed aspirator, constant depth groove third program cycle and a fixed sample probe, variable depth groove fourth program cycle disposed on the second cam face of said cam opposite said first cam face, said first and second cam faces disposed normal to the cam axis of rotation, said cam having at least a pair of fixed switch actuating lobes symmetrically oppositely disposed on the cam face parallel to said cam axis of rotation, one of said pair of switch lobes positioned to terminate the first one-half of said timing cycle, the above said programming cycles and said switch lobes synchronously sequentially disposed to control predetermined arc intervals of said cycle relating to sample intake probe position, the sample liquid volume, the diluent liquid volume, the sample and diluent liquid mixture volume, the diluted sample liquid volume aspiration, and the system diluent liquid rinse volume and ejection.
 12. A sample dilutor as set forth in claim 11 wherein the timing one-half cycle of said program cam is less than 10 seconds.
 13. An apparatus set forth in claim 11 wherein a hydrophobic sample probe tip is removed from an aqueous sample liquid surface at a linear velocity of less than
 1. inch per second.
 14. In an automated liquid sample handling device suitable for supplying sample to the sample intake of a chemical analyzer, said device including pump means, valve means for controlling the flow of liquid to and from said pump means, a sample intake and delivery probe, an aspirator probe for connection to said analyzer and a sample cup, the improvement which comprises: a single rotary program cam and power means for rotating said cam, said cam having formed therein multiple program profile means for sequentially controlling over a predetermined cycle the operation of said pump and valve means, and the position of said sample intake and delivery probe and said aspirator probe with respect to said sample cup, said profile means effecting vertical and horizontal translation of said sample intake and delivery probe and vertical translation of said aspirator probe.
 15. A device as set forth in claim 14 wherein said program cam has at least two discrete profile means disposed on each one of the pair of cam faces normal to the cam axis of rotation. 